I have a 2003 Super Z with the 60 inch deck. There is 159 hours on the mower and the deck has gotten progressively worst as far as noise goes. I have tightened the belt and checked the spindles for wear and everything seems fine. In the past I have replaced a couple of pulleys that were defective. The noise is now to the point that it actually hurts your ears. (I know, ear protection should be worn). This is not normal from my expereince with other zero turns mowers I have had. The noise I'm refering to is high is not exactly a whine but is somewhat high pitched. Any idea as to what I could do to resolve this problem. Could it be the belt with this low amount of hours?